$ cat /etc/apt/sources.list
deb http://raspbian.raspberrypi.org/raspbian/ bullseye main contrib non-free rpi
# Uncomment line below then 'apt-get update' to enable 'apt-get source'
# deb-src http://raspbian.raspberrypi.org/raspbian/ bullseye main contrib non-free rpi
# or
$ cat /etc/apt/sources.list
deb http://raspbian.raspberrypi.org/raspbian/ bullseye main contrib non-free rpi
deb http://deb.debian.org/debian bullseye main contrib non-free
deb http://security.debian.org/debian-security bullseye-security main contrib non-free
deb http://deb.debian.org/debian bullseye-updates main contrib non-free
/etc/apt/sources.list.d/raspi.list
$ cat /etc/apt/sources.list.d/raspi.list
deb http://archive.raspberrypi.org/debian/ bullseye main
# Uncomment line below then 'apt-get update' to enable 'apt-get source'
# deb-src http://archive.raspberrypi.org/debian/ bullseye main